U.S. patent number 10,787,266 [Application Number 16/655,802] was granted by the patent office on 2020-09-29 for fan bypass and shutoff check valve.
This patent grant is currently assigned to HAMILTON SUNSTRAND CORPORATION. The grantee listed for this patent is Hamilton Sundstrand Corporation. Invention is credited to Donald E. Army, Frederick Peacos, III.
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United States Patent |
10,787,266 |
Army , et al. |
September 29, 2020 |
Fan bypass and shutoff check valve
Abstract
A ram air fan and fan bypass shutoff check valve assembly
includes a ram air fan configured to draw an airflow through a fan
inlet, and a ram fan bypass duct positioned downstream of the ram
air fan. The ram fan bypass duct includes a valve assembly
configured to selectably direct the airflow through the ram air fan
when the valve assembly is in an open position, and direct the
airflow through a bypass duct thereby bypassing the ram air fan
when the valve assembly is in a closed position.
Inventors: |
Army; Donald E. (Enfield,
CT), Peacos, III; Frederick (North Scituate, RI) |
Applicant: |
Name |
City |
State |
Country |
Type |
Hamilton Sundstrand Corporation |
Charlotte |
NC |
US |
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Assignee: |
HAMILTON SUNSTRAND CORPORATION
(Charlotte, NC)
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Family
ID: |
1000005081530 |
Appl.
No.: |
16/655,802 |
Filed: |
October 17, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200047891 A1 |
Feb 13, 2020 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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15481661 |
Apr 7, 2017 |
10486816 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B64D
13/06 (20130101); F04D 19/02 (20130101); B64D
41/007 (20130101); F04D 27/0215 (20130101); B64D
2013/0618 (20130101); B64D 2013/0603 (20130101); B64D
13/02 (20130101) |
Current International
Class: |
B64D
13/06 (20060101); F04D 27/02 (20060101); F04D
19/02 (20060101); B64D 13/02 (20060101); B64D
41/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1805658 |
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Jul 1970 |
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DE |
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9105673 |
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May 1991 |
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WO |
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Other References
European Search Report Issued in EP Application No. 18166271.9,
dated Sep. 12, 2018, 8 Pages. cited by applicant.
|
Primary Examiner: Ma; Kun Kai
Attorney, Agent or Firm: Cantor Colburn LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. patent
application Ser. No. 15/481,661 filed Apr. 7, 2017, the contents of
which are incorporated by reference herein in their entirety.
Claims
What is claimed is:
1. A check valve for a ram air fan assembly, comprising: a support
having a plurality of support openings therein in fluid
communication with a bypass duct; an inner cage disposed in the
support having a plurality of cage openings therein; and a
plurality of flappers rotatably secured to the inner cage, the
plurality of flappers movable between the open position covering
the plurality of support openings, and the closed position covering
the plurality of cage openings; wherein each flapper of the
plurality of flappers includes a spoiler extending from an outer
surface of the flapper over which the airflow from a bypass duct is
directed to urge the flapper into the closed position.
2. The check valve of claim 1, wherein the plurality of flappers
are biased to the closed position.
3. A check valve for a ram air fan assembly, comprising: a support
having a plurality of support openings therein in fluid
communication with a bypass duct; an inner cage disposed in the
support having a plurality of cage openings therein; and a
plurality of flappers rotatably secured to the inner cage, the
plurality of flappers movable between the open position covering
the plurality of support openings, and the closed position covering
the plurality of cage openings; wherein the inner cage includes: a
hub; an outer ring; and a plurality of spokes extending from the
hub to the outer ring, the plurality of cage openings formed
between adjacent spokes of the plurality of spokes.
4. The check valve of claim 3, wherein the plurality of spokes are
aerodynamically shaped.
Description
BACKGROUND
Exemplary embodiments pertain to aircraft environmental control
systems. More particularly, the present disclosure relates to a
bypass control of a ram air fan for an aircraft environmental
control system.
Environmental control systems (ECS's) supply airflow to an interior
of an aircraft to condition, for example, a passenger cabin, crew
compartment and/or cargo compartment. In some ECS architectures a
ram air fan is utilized to draw ram air into the ECS and across a
ram air heat exchanger to condition a fluid flowing through the ram
air heat exchanger. The ram air fan is driven by, for example an
electric motor or a turbine. The typical air bearing ram air fan is
not required to operate during flight for performance reasons, but
will uncontrollably windmill during flight, if not driven by an
electric motor or turbine. To control ram air fan rotation during
flight and to keep the rotating assembly supported by an air film,
the ram air fan is typically powered to operate at a specified
minimum speed.
BRIEF DESCRIPTION
In one embodiment, a ram air fan and fan bypass shutoff check valve
assembly includes a ram air fan configured to draw an airflow
through a fan inlet, and a ram fan bypass duct positioned
downstream of the ram air fan. The ram fan bypass duct includes a
valve assembly configured to selectably direct the airflow through
the ram air fan when the valve assembly is in an open position, and
direct the airflow through a bypass duct thereby bypassing the ram
air fan when the valve assembly is in a closed position.
Additionally or alternatively, in this or other embodiments the
valve assembly includes a support having a plurality of support
openings therein in fluid communication with the bypass duct, an
inner cage positioned in the support having a plurality of cage
openings therein, and a plurality of flappers rotatably secured to
the inner cage. The plurality of flappers are movable between the
open position covering the plurality of support openings, and the
closed position covering the plurality of cage openings.
Additionally or alternatively, in this or other embodiments the
plurality of flappers are biased to the closed position.
Additionally or alternatively, in this or other embodiments each
flapper of the plurality of flappers includes a spoiler extending
from an outer surface of the flapper over which the airflow from
the bypass duct is directed to urge the flapper into the closed
position.
Additionally or alternatively, in this or other embodiments the
inner cage includes a hub, an outer ring, and a plurality of spokes
extending from the hub to the outer ring. The plurality of cage
openings are formed between adjacent spokes of the plurality of
spokes.
Additionally or alternatively, in this or other embodiments the
plurality of spokes are aerodynamically shaped.
Additionally or alternatively, in this or other embodiments the
plurality of flaps rotate less than 45 degrees between the open
position and the closed position.
Additionally or alternatively, in this or other embodiments airflow
through the bypass flow and airflow through the ram air fan exit
the ram air fan assembly at a common passage exit.
In another embodiment, an environmental control system for an
aircraft includes a ram air heat exchanger and a ram air fan
assembly operably connected to the ram air heat exchanger and
configured to urge an airflow across the ram air heat exchanger.
The ram air fan assembly includes a ram air fan and a ram fan
bypass duct positioned downstream of the ram air fan. The ram fan
bypass duct includes a valve assembly configured to selectably
direct the airflow through the ram air fan when the valve assembly
is in an open position, and direct the airflow through a bypass
duct thereby bypassing the ram air fan when the valve assembly is
in a closed position.
Additionally or alternatively, in this or other embodiments the
valve assembly includes a support having a plurality of support
openings therein in fluid communication with the bypass duct, an
inner cage located in the support having a plurality of cage
openings therein, and a plurality of flappers rotatably secured to
the inner cage. The plurality of flappers movable between the open
position covering the plurality of support openings, and the closed
position covering the plurality of cage openings.
Additionally or alternatively, in this or other embodiments the
plurality of flappers are biased to the closed position.
Additionally or alternatively, in this or other embodiments each
flapper of the plurality of flappers includes a spoiler extending
from an outer surface of the flapper over which the airflow from
the bypass duct is directed to urge the flapper into the closed
position.
Additionally or alternatively, in this or other embodiments the
inner cage includes a hub, an outer ring, and a plurality of spokes
extending from the hub to the outer ring. The plurality of cage
openings are formed between adjacent spokes of the plurality of
spokes.
Additionally or alternatively, in this or other embodiments the
plurality of spokes are aerodynamically shaped.
Additionally or alternatively, in this or other embodiments the
plurality of flaps rotate less than 45 degrees between the open
position and the closed position.
In yet another embodiment, a check valve for a ram air fan assembly
includes a support having a plurality of support openings therein
in fluid communication with the bypass duct, an inner cage
positioned in the support having a plurality of cage openings
therein, and a plurality of flappers rotatably secured to the inner
cage. The plurality of flappers are movable between the open
position covering the plurality of support openings, and the closed
position covering the plurality of cage openings.
Additionally or alternatively, in this or other embodiments the
plurality of flappers are biased to the closed position.
Additionally or alternatively, in this or other embodiments each
flapper of the plurality of flappers includes a spoiler extending
from an outer surface of the flapper over which the airflow from a
bypass duct is directed to urge the flapper into the closed
position.
Additionally or alternatively, in this or other embodiments the
inner cage includes a hub, an outer ring, and a plurality of spokes
extending from the hub to the outer ring, the plurality of cage
openings formed between adjacent spokes of the plurality of
spokes.
Additionally or alternatively, in this or other embodiments the
plurality of spokes are aerodynamically shaped.
BRIEF DESCRIPTION OF THE DRAWINGS
The following descriptions should not be considered limiting in any
way. With reference to the accompanying drawings, like elements are
numbered alike:
FIG. 1 is schematic view of an embodiment of an environmental
control system for an aircraft;
FIG. 2 is a first cross-sectional view of an embodiment of a ram
air fan and fan bypass/shutoff check valve assembly;
FIG. 3 is a second cross-sectional view of an embodiment of a ram
air fan and fan bypass/shutoff check valve assembly;
FIG. 4 is a partial perspective view of an embodiment of a ram air
fan and fan bypass/shutoff check valve assembly;
FIG. 5 is a partially exploded view of an embodiment of a ram air
fan and fan bypass/shutoff check valve assembly;
FIG. 6 is another partial perspective view of an embodiment of a
ram air fan and fan bypass/shutoff check valve assembly;
FIG. 7 another cross-sectional view of an embodiment of a ram air
fan and fan bypass/shutoff check valve assembly; and
FIG. 8 is yet another cross-sectional view of an embodiment of a
ram air fan and fan bypass/shutoff check valve assembly.
DETAILED DESCRIPTION
A detailed description of one or more embodiments of the disclosed
apparatus and method are presented herein by way of exemplification
and not limitation with reference to the Figures.
The term "about" is intended to include the degree of error
associated with measurement of the particular quantity based upon
the equipment available at the time of filing the application. For
example, "about" can include a range of .+-.8% or 5%, or 2% of a
given value.
The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the present disclosure. As used herein, the singular forms "a",
"an" and "the" are intended to include the plural forms as well,
unless the context clearly indicates otherwise. It will be further
understood that the terms "comprises" and/or "comprising," when
used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components,
but do not preclude the presence or addition of one or more other
features, integers, steps, operations, element components, and/or
groups thereof.
Referring to FIG. 1, a schematic illustration of an environmental
control system (ECS) 10 for an aircraft is shown. The ECS 10
includes a ram air heat exchanger 12 and a ram air fan assembly 14
to draw a ram airflow 16 across the ram air heat exchanger 12 to
condition a fluid flowing through the ram air heat exchanger 12.
The ram airflow 16 then flows through ram air passage 18, through
the ram air fan assembly 14 and out of a passage exit 20.
Referring to FIG. 2, the ram air fan assembly 14 includes a fan
housing 22, in which a ram air fan 24 is located, and is rotatable
about a central axis 26. The fan housing 22 is in flow
communication with the ram air duct 28 downstream of the ram air
heat exchanger 12. In the embodiment illustrated, the ram air fan
24 is driven by a tip turbine 30 located in the fan housing 22
radially outboard of the ram air fan 24. A ram fan bypass duct 32
is located downstream of the fan housing 22 and includes a fan
bypass/shutoff check valve consisting of an outer housing 34 and an
inner cage 36 located therein. The outer housing 34 includes a
support 38 and a plurality of flappers 40 rotationally movable
between an opened position shown in FIG. 2 in which airflow 42
proceeds through the ram air fan 24 and through the passage exit
20, and a bypass position, shown in FIG. 3, in which airflow 42
bypasses the ram air fan 24 and proceeds through a bypass passage
44 in the ram fan bypass duct 32 to the passage exit 20.
Referring now to FIG. 4, the support 38 includes a plurality of
support openings 46, the quantity of support openings 46
corresponding to the quantity of flappers 40 in the plurality of
flappers 40. In some embodiments, there are 8 support openings 46
and 8 flappers 40, but it is to be appreciated that other
quantities may be used. When in the opened position, as shown in
FIG. 2 and FIG. 4, each flapper 40 engages to the support 38,
closing a respective support opening 46. In some embodiments, the
support openings 46 are recessed into the support 38 such that when
the flapper 40 engages the support 38 at the support opening 46 an
inner flapper surface is flush with an inner support surface, such
that there is a positive seal and a smooth flowpath along the inner
support surface, reducing pressure drop along the support 38.
Further, the inner cage 36 includes a plurality of inner cage
openings 48, shown best in the exploded view of FIG. 5. In the view
of FIG. 2 and FIG. 4, with the flappers 40 in the opened position,
the airflow 42 is directed from the ram air fan 24, through the
plurality of inner cage openings 48, and through the passage exit
20. When the ram air fan 24 is operating, positive air pressure
across the ram air fan 24 forces the flappers 40 into the opened
position.
FIG. 6 further illustrates the plurality of flappers 40 in a closed
position. When in the closed position, the flappers 40 engage the
inner cage 36 covering the plurality of inner cage openings 48.
Referring to FIG. 3, with the inner cage openings 48 covered, the
airflow 42 is diverted through the bypass passage 44 and to the
passage exit 20, bypassing the ram air fan 24.
The flappers 40 are each connected to the support 38 via, for
example, a hinge connection 50 at a pivot axis 52. To move between
the open position, illustrated in FIG. 2 and the closed position
illustrated in FIG. 6, the flapper 40 is rotated about the pivot
axis 52. In some embodiments, an angle of rotation of the flapper
40 between the open position and closed position is less than 45
degrees. In other embodiments, the angle of rotation is 40
degrees.
In some embodiments, the flappers 40 are biased toward the closed
position by, for example, a spring or other biasing device (not
shown). When the ram air fan 24 is commanded to stop, the flappers
40 move to the closed position due to the lack of positive pressure
across the ram air fan 24, and because of the influence of the
biasing device. Further, in some embodiments, as shown in FIG. 7,
the flapper 40 includes an aerodynamic spoiler 56 extending from an
outer surface 58 of the flapper 40, such that the airflow 42
flowing though the bypass passage 44 flows over the spoiler 56,
exerting aerodynamic forces on the spoiler 56 and urging the
flappers 40 into engagement with the inner cage 36 covering the
cage openings 48. In some embodiments, the spoiler 56 extends
substantially perpendicularly to a direction of the airflow 42
exiting the bypass passage 44.
Referring again to FIG. 5 and FIG. 7, the inner cage 36 includes a
hub 60 located at the central axis 26 and an outer ring 62 coaxial
with the hub 60 and defining a radial outwardmost extent of the
inner cage 36. A plurality of spokes 64 extend from the hub 60 to
the outer ring 62 defining the cage openings 48 between adjacent
spokes 62. As shown in FIG. 8, the spokes 64 each have a
cross-sectional shape configured to reduce pressure drop through
the cage openings 48. As shown the spokes 64 may have a tapered V
cross-sectional shape, or alternatively another cross-sectional
shape, such as an airfoil shape.
The ram fan bypass duct 32 including the inner cage 36 and flappers
40 movable between the inner cage 36 and the support 38, allows
airflow 42 to bypass the ram air fan 24 in-flight thus preventing
windmilling of the ram air fan 24 and preventing the need to power
the ram air fan 24 during flight to provide airflow to an air
bearing of the ram air fan 24.
While the present disclosure has been described with reference to
an exemplary embodiment or embodiments, it will be understood by
those skilled in the art that various changes may be made and
equivalents may be substituted for elements thereof without
departing from the scope of the present disclosure. In addition,
many modifications may be made to adapt a particular situation or
material to the teachings of the present disclosure without
departing from the essential scope thereof. Therefore, it is
intended that the present disclosure not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this present disclosure, but that the present
disclosure will include all embodiments falling within the scope of
the claims.
* * * * *